lance armstrong comes clean. after more than a decade of denials, lies and cheating, seven-time tour de france winner, olympic bronze medalist and cancer survivor lance armstrong told oprah winfrey the truth. >> did you ever take banned substances to enhance your cycling performance? >> yes. >> yes or no. was one of those banned substances epo? >> yes. >> did you ever blood dope or use blood transfusions to enhance your cycling performance? >> yes. >> did you ever use any other banned substances like testosterone, cortisone or human growth hormone? >> yes. >> yes or no, in all seven of your tour de france victories, did you ever take banned substances or blood dope? >> yes. >> in your opinion, was it humanly possible to win the tour de france without doping? seven times in a row. >> not in my opinion. >> for months, even longer, armstrong has been feeling the effects of the latest and biggest u.s. anti-doping investigation. this one found him guilty of using illicit drugs throughout his cycling career. now his to